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(No Model.) 2 Sheets-Sheet 1.

W. J. LEWIS.

v VALVE GEAR FOR DUPLEX PUMPS. No. 326,996. Patented Sept. 29, 1885.

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(No Model.) 2 SheetQ-Sheet 2. W. J. LEWIS.

VALVE GEAR FOR DUPLEX PUMPS. No. 326,996. Patented Sept. 29, 1885.

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WALLACE JAMES LEWIS, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO W. A.SAMPSON, OF SAME PLACE.

VALVE-GEAR FOR DUPLEX PUMPS.

SPECIFICATION forming part of Letters Patent No. 326,996, datedSeptember 29, 1885.

Application filed July 22, 1885.

To all whom it may concern.-

Be it known that I, WALLACE J. LEWIs, a resident of Chicago, in thecounty of Cook and State of Illinois, have invented certain new anduseful Improvements in Valve-Gear for Duplex Pumps, of which thefollowing, when taken in connection with the drawings accompanying thesame and forming a part thereof, is a full and complete description,sufficient to enable those skilled in the art to which it appertains toconstruct and use thesame.

My invention relates to duplex steam-pumps; and the object of myinvention is, primarily, to secure a constant and unvarying length ofstroke in the piston of the duplex pump to which it is attached, withoutreference to and independent of the speed or number of strokes ormovements per minute ofzsaid piston; and, further, to obtain a full andcomplete movement of the valve operated by my said improvement; and,secondarily, to Eattain an effective and easy method of securing,adjusting, and controlling a lap and lead, so called, in said valve onthe seat thereof.

I have illustrated my invention as attached to a duplex pump havingauxiliary exhaustports.

Figure 1 is an elevation of myinvention with a portion of cylinderbroken away, showing the valve and valve-seat in section. Fig. 2 is anend elevation. Fig. 3 is an end elevation on an enlarged scale, showingthe main and auxiliary crank used in my invention, the main crank beingshown in part section.

Like letters refer to like parts throughout the several views.

V V are the piston-rods.

V is a sleeve on each of said piston-rods 40 V V.

V is a rod or link connection between sleeve V and bell-crank F.

X is the steam-cylinder.

X is the valve-seat.

Y is an ordinary slide-valve.

Y Y are ports, used in the construction here illustrated as steam-ports.

Y Y are exhaust-ports.

Z is the block or nut on valve. Y.

Z Z are the valve-stems.

A is a quarter-crank shaft.

Shaft A makes (No model.)

one revolution to each completed movement of Valve Y.

' a. a are cranks on shaft A.

B is the crank-pin.

b is a tapering portion of crank-pin B.

I) is an ordinary nut on crank-pin B.

C C are the heads of crank-pin B.

C C are pins in heads C C of crank-pin B.

D D are valve-rods. O

E E are rods connecting bell-crank F F and crank-shaft A.

F F are bell-cranks.

f f are the fulcrums on which bell-cranks F F rock or vibrate.

e e are pins.

e c are pins.

The dotted lines indicate the relative position of the differentduplicated parts shown to the right and left in Fig. 2. Crank-shaft A,Fig. 2, is continuous, being illustrated as broken in said figure toindicate that pistonrods V V may be any desired distance apart.

The operation of my invention is: Pistonrod V being in the positionillustrated (clearly indicated in Fig. 2) by the dotted lines in Fig. 1,steam is admitted in port Y, on the right-hand side in the drawings, andthe pistonrod is moved thereby in the direction indicated by the arrowover said piston-rod in Fig. 1. 8 This movement of the piston-rod causescrank shaftAto revolve in the direction of the arrow over said shaft.

It will be observed that in the position said valve Y is, as indicatedby the dotted lines in 3 Fig. 1, it is fully opened, and the piston andbell-crank, as indicated also by the dotted lines in said figure, areeach in about the middle of the forward stroke or movement. Thequarter-rotation of crank-shaft A, as described, will cause the valveillustrated by the dotted lines to assume the position of the valveindicated by the full lines in said figure, and at the same time thepiston-rod will have completed its forward movement or stroke. Furtherrotation of crank-shaft A causes the steam-port on the opposite end ofthe steam-cylinder to open, and at the same time opens the exhaust-portto the right (in the drawings) of the steamcylinder, thus permittingsaid piston to be forced back on its return-stroke. WVhile said pistonis completing the forward movement,

as above described, crank-pin B, Fig. 1, is carried overits"dead-.center, so called, and by the time the pin B (indicated by thedotted lines, Fig. 1) has reached its dead-center further revolution ofcrank-shaft A is maintained by piston and bell-crank indicated by thefull lines. A constant rotary movement is thus imparted to crank-shaftA, the amount of force imparted to said shaft by the said belleranks andtheir connections constantly vary ing, though working in unison orcollectively to maintain the rotary movement of said shaft A. 1

By the tapering portion Z) of erankpin B, and nut b thereon, I am ableto so adjust pins 0 O that the circle described by said pins may belarger or smaller to a given extent, and I thus secure and control a lapor lead in the valve.

Having described my invention, what I claim, and desire to secure byLetters Patent,

1. In a valve-gear for duplex pumps, a quarter crank shaft having eachcrank provided with an auxiliary crank thereon, connected with thesteam-valve of said pump, in combination with bell-cranks havingrod-connection with the piston-rods of said pump and with saidquartencrank shaft, all substantially as described, and for the purposespecified.

2. In a valve-gear for duplex pumps, a quarter-crank shaft having eachcrank provided with an auxiliary crank thereon,adjustab1y attachedthereto and connected with the steamvalve of said pump, in combinationwith bellcranks having rod-connection with the pistonrods of said pumpand with said quarter-crank shaft, all substantially as described, andfor the purpose specified.

WALLACE JAMES LEWIS.

lVitnesses:

CHARLES I. BROWN, D. W. Evans.

